日東化成工業株式会社 manufactures 耐火パテ and non-combustible putties for sealing 防火区画貫通部, marketed as complete 工法 rather than loose materials. Its NF-12HM system holds 国土交通大臣認定 区画貫通部 approvals PS060WL-1318 and PS060WL-1316 for 60-minute fire-rated hollow walls, and other systems hold 日本消防設備安全センター 評定工法 status. It runs a research institute and factory in Bizen, Okayama.